Mice Can No Longer Remember Elephants Being Afraid Of Them
Remember those movies that show devices used to erase the mind? Well, now researchers may be one step closer to that process. Scientists have now been able to remove certain memories from mice.
“While memories are great teachers and obviously crucial for survival and adaptation, selectively removing incapacitating memories, such as traumatic war memories or an unwanted fear, could help many people live better lives,” says Dr. Joe Z. Tsien, brain scientist and co-director of the Brain & Behavior Discovery Institute at the Medical College of Georgia School of Medicine. “Our work reveals a molecular mechanism of how that can be done quickly and without doing damage to brain cells.”
Dr. Tsien and his team were able to remove new and old memories by over-expressing a protein critical to brain cell communication just as the memory was recalled.
By eliminating the NMDA receptor, Dr. Tsien created a mouse that couldn’t form memories. He then created a smart mouse named ‘Doogie’, in which a subunit of the NMDA receptor was over-expressed. Wanting to learn more about memory formation, he discovered that when αCaMKII – a protein found only in the brain – was over-expressed while a memory was in the process, that single memory could be removed.
Dr. Tsien’s team developed a chemical-genetic method allowing him to use a pharmacologic inhibitor to instantly turn αCaMKII off and on in a mouse that he genetically engineered to over-express this signaling molecule. Through this method, he was able to study the effects of throwing off the natural balance during the retrieving stage.
Researchers also tested object recognition memory, where they gave mice a few toys to play with and then erased their memory of one of them. “You will feel like every time, it’s a new toy,” says Dr. Tsien.
Dr. Tsien states that while being able to erase selective memory is exciting, using it on humans would be difficult at this point in time. “We are barely at the foot of a huge mountain,” says Dr. Tsien.
This research was funded by the National Institute of Mental Health, the National Institute on Aging and the Georgia Research Alliance.